In the process of production of IC devices and other electronic devices, an electronic device test apparatus is used to test the IC devices for performance and functions in the state formed on the wafer or in the packaged state.
As an apparatus 1′ for testing IC devices formed on a wafer W for their electrical characteristics, as shown in FIG. 15, there has been known in the past an apparatus using a prober 70 to push the wafer W against a probe card 50 to bring the probe needles 51 of the probe card 50 into electrical contact with the electrodes of the IC devices and testing the IC devices for electrical characteristics via the probe card 50 and a test head 10 by a tester (not shown). A large number of connectors 53 for electrical connection are arranged at the outer periphery of the probe card 50, while a large number of probe needles 51 are arranged at the center part of the probe card 50.
In this apparatus 1′, as shown by the broken line arrows X in the figure, the pushing force of the prober 70 pushing the wafer W against the probe card 50 is transmitted through a circular end face holder 60 and an adapter 65 to a housing 71 of the prober 70, so sometimes this pushing force causes the center part of the probe card 50 where the probe needles 51 are provided to bend and deform. In particular, along with the increase in the number of simultaneous measurements in recent years, a further larger number of probe needles 51 have to be mounted on the probe card 50. As a result, the required pushing force is further increased. Further, bending and deformation of the probe card 50 lead to differences in the contact pressure among the probe needles 51, so stable electrical contact is obstructed and contact failure sometimes occurs. These destabilizing factors lead to deterioration of the test quality.
As opposed to this, a stiffener 54 reinforcing the probe card 50 can be increased in rigidity so as to prevent deformation of the probe card 50, but the change in material and shape lead to an increase in costs and the increase in weight obstructs handling of the probe card at the time of change of the type of devices tested. Further, the temperature conditions under which the tests are conducted fluctuate from a high temperature to a low temperature, so measures have to be taken against the heat expansion of a printed circuit board 52 or a stiffener 54 of the probe card 50. Further, the probe card 50 changed in accordance with the type of the wafer W under test will sometimes differ in board thickness, so a large number of types of stiffeners 54 would have to be prepared to fit with many kinds of the probe card 50.